Leo's what tell tale signs do you give off if you like someone?

I am crushing really hard on this Leo I've met. We met on holiday, and we've been talking afterwards, but in the last week or so he's kinda gone off the map. He sends through things on Snapchat still, but in our fb messenger conversation i was the last to write and he hasn't replied!

I don't want to feel like I'm pestering him you see!

But yeah leos what signs do you give off if someone's sparked your interest? Just wondering